Means for producing articles from granular or plastic substances



Oct 29, 1929. K. a. w. PETTERSSON j 1,733,513

MEANS FOR PRODUCING ARTICLES FROM GRANULAR OR PLASTIU SUBSTANCES FiledDec.,29, 1927 Patented Oct. 29, 1929 rona rron o a a ;A rgunorFlC I KNUTGUNNAR wnntmtrm rngrrnnsson, or i vas riines, SWEDEN,-ASSIG1\TOR To" lAKTIEBOLAGET 'LINDHOLMENMOTALA,

orfivro'rnna vnRKsrAn sWnnEN, A 003- MEANS ron 'rnomrcrne lmrrcnns menchariot-Anon rLAsmoI-snnsmnces .appnoationmea sam a 2a, 1927, semi No.a4s,412, ana n1 Sweden May 29, 1926.

In making-casting molds from sand or other granular material, it ishitherto a common praxis to subject the casting box or flask to astrongshaki-ng movement in a verticaldi rection. This has generally beenperformed in such a manner that the downward movement has been suddenlyinterrupted, and especially at the shocksth ereby caused the grains havebeen'packed together in the desired manner. The total movement j hasneecssarily been rather large, in order to pro-' duce a suflioiently"strong shock, and during the majorpart of this movement no real packing of the grains has taken place. A close examination of this processtherefore shows it to be of rather smallefliciency.

According to the present invention, the moldor casting box togetherwi'ththe granular material, such as sand contained therein, is subjectedto rapid vibrations for packing the said material together. It appearsat the first thought that such vibrations which involve alternating,practically equal forces acting on the grains in opposite directions,would not cause an efficient packing of the grains. The experience,however, proves that a much greater force is necessary for loosening thegrains after they have once been squeezed in between each other by wedgeaction, than for the said squeezing in, and the result will be thatpractically every change in the direction of movement will increase thepacking effect, if the vibration process is used, whereas in the oldshaking process a packing takes place only when the direction ofmovement is reversed from downward to upward. Theoretically, if themaximum retardation is the same and other circumstances equivalent inboth cases, the proportion between the working speeds of the twoprocesses would therefore be about twice the proportion between thefrequencies. In practice it has also been found that a very considerablesavin of time is obtained. Further it is possi le with this process tomanufacture much smaller cores, molds and the like than by the shakingprocess. I It is advisable to subject the sand or other materal toalight pressure during the vibra-' tion. For smaller objects, the saidpressure can be exerted by hand; for larger objects,

a pressv plate or the like may be employed, 1 i

serving as a counter support against the vibratory motlon.

The frequency of the vibrations employed I may vary within ratherwidelimits. As a lower limit, ten complete cycles per second may bechosen, this being at any rate considerably more than has been used inthe shaking process, that is, about five cycles per" second as amaximum. Generally it is,"however, advisable to employ between 30 and I100 cycles per second, The vibrations may be either single,reciprocating in a certain direction, or complex, alternately 1n variousdirections forming angles with each other.

They may also, ifdesired, be ofa moreirregu l-ar character. Theintroduction of thesand or other material may take place either beforethe beginning of the vibrations or gradually during the saidvibrationsand in either case bemade by any kind of filling means.

The invention is applicable also in making I I keramicand cementatoryobjects, such as p1pes,bricks and the like to be produced in amold,-said, mold and the cement, clay or other suitable materialcontained therein be- I ingsubjected tovibrations in the manner set f ai J r The inventionalso relates to means for exe outing the process,comprising a movable table or other support for the flask orcastingboxcarried by one or more mechanically or electrically drivenvibrators adapted to set the support with the objects carried thereby invibrations. lf desired, the vibrators may instead be carried by thetable] I I i I In the accompanying drawing, two embodiments of a machinefor'carrying'the process into elfect are illustrated] Fig- 1 shows amolding machine in elevation, partlyin section and Fig. 2' shows adetailof a modified form ofthe upper portion of the machine shown inFig,in elevation and partial section. a

s 1 {Referring to Fig. '1, ram 1, which my tiltablein a stand 2m aknown;manner, a

is provided at its lower part with-guiding grooves Sin whichavibratorcylinder'i containing a iston 12 ismovableup. and down.

The cylin er carries, at its top a tablet for the, casting box 6. Placedon the latter is a separate filling hopper or frame 7 which may bepartially or totally filled with sand or corresponding material duringthe operation.

The table '5 is carried by the cylinder 4 by means of bolts 8 secured tothe'former and traversing guide holes in projections 9 on the cylinder.vThe bolts are surrounded by springs 10 which normallypress the table 5downwards into its lowest position. By

7 means of set screws 11, the bolts 8 may be lockedto the guidingprojections 9 so that the table is held firml to the cylinder. Theresilient connection with loose set screws) is used for big objects, therigid connection for small ones, for which'the deformation of thematerial provides for sufiicient vibrations.

For accelerating the compression of the material to be molded,especially in the upper layers, a press plate 13 may be used, which forinstance may be lifted by means of a hand wheel 14, and which accordingto Fig. 1 is presumed to be so heavy that its own weight is suflicientfor the compression, so that no readjustm'entis necessary for packingthe sand.

For molding small objects, the said press plate may not be necessary, asa pressure by hand maybe suflicient. For such cases, the upper portionof the frame 1 may be swung to the side on'a hinge 15. Withthe machineillustrated, two or more objects placed on one another mav be molded,for instance the two halves of a divided casting mold or c0re.

' The cylinder 4 is, asalready stated, some what movable in the frame ina vertical disupport carried by said vibrator, and means for compressingsaid granular substances.

4. A machine for making molds from granular substances, comprising aframe, a vibrator resiliently carried by said frame, a mold supportcarried by said vibrator, and means for exerting vibratory pressure onobjects carried by said support.

5. A machine for making-goods from granular or plastic substances,comprising a frame, a vibrator resiliently carried by said frame, and amold support connected to said vibrator.

6. In a machine for making molds from granular materials, a frame, amold support on said frame, a. castingbox on said support for receivinggranular material, resiliently mounted means for applying vibratorymovement-to said mold support and; means for simultaneously applyingpressure to the granular material in said casting box.

' rection and resiliently supported in the same I by means of springs 16surrounding bolts 17 This movement can be'arrested by means of latches18 which is especially desirable when the, frame shall be tilted forextracting the mold or core. i

In the modified embodiment of the machine 7 shown in Fig. 2, the plate13 is carried by means of bolts 19and springs 20 by a vibrator icylinder 21, which in its turn is carried by the piston-rod 22 of acylinder 23 mounted on the frameand serving to exert pressure during themolding and to lift the plate. (to which the molded object or partthereof may be fixed) after the said operation.

r p Whilll'I claim is:-

1. .A machine for making molds from granular substances, comprising aframe, a

vibrator resiliently carried by said frame,- and V f amoldjsupportcarried by said vibrator.

2. A machine for making molds from gran- 7 i ular substances, comprisinga frame, a vibra tor resiliently carried by sa1d frame, 'a'de'vlce for"locking 'said"v ibrator rigidly to. said support I carried by saidframe, and a mold vibratonf 3. Amachine for making molds from granularsubstances, comprising a frame, a vibrajtor resiliently carried by saidfranie,a mold

